A. Field of the Invention
The present invention relates generally to the field of minimally invasive surgical instruments, and more particularly, to a visual blade retractor system which will allow greater access and visual exposure in the surgical area, along with improved instrument control, orientation and versatility.
B. Description of the Prior Art
Minimally invasive surgical techniques have become increasingly popular due to the rapid healing and greater efficiency provided by such techniques. As these techniques have been developed, workers and surgeons have been faced with the problem of working in small places not visible by direct line of sight. Various tools have been designed to deal with this problem although none has been entirely satisfactory.
The standard surgical approach has been to make a large enough opening in an anatomically suitable location (which will heal without functional impairment) to establish direct visualization. Magnification can then be used to enlarge the target structure and various fiberoptic light or scope delivery systems can be used to illuminate it. The actual surgical manipulation is then performed by direct manipulation of instruments held in the surgeons' hands. Even with the advent of minimally invasive surgical techniques, many surgical procedures still require an exposed surgical field for the surgeon to successfully perform. Often, the greater the visibility and access a surgeon has to a surgical site, the greater the probability that a successful outcome will result. Once entry is made into a patient, soft tissue is dissected away further exposing the field. However, the exposed field must be maintained using instruments that do not obstruct either visual or physical access. Surgical retractors are used to maintain exposure and access to a surgical field. There are a variety of retractors, and different surgical protocols require different styles of retractors. For example, in lumbar surgery the retractor needs to be strong enough to overcome the force exerted by the large muscle mass that has been dissected away from the field of exposure, while maintaining a visual field and access by the surgeon. Additionally, retractors are often required to partition other soft-tissue components of the surgical field.
One example of the need for improvements in minimally invasive surgery is in the area of minimally invasive spinal surgery. Modem spinal surgical techniques, for example, often call for the implantation of fusion devices into the disc space. These methods include anterior, lateral, postero-lateral and posterior approaches to the subject disc space. Many traditional surgical procedures for correction of disc space pathologies can cause significant trauma to the intervening tissues. These open procedures often require a long incision, extensive muscle stripping, prolonged retraction of tissues, denervation and devascularization of tissue. Most of these surgeries require significant post-operative recovery time due in part to the necessary destruction of tissue during the surgical procedure. Minimally invasive surgical techniques are particularly desirable for spinal and neurosurgical applications because of the need for access to locations deep within the body and the danger of damage to vital intervening tissues. The development of minimally invasive spinal procedures has yielded a major improvement in reducing recovery time and post-operative pain because they require minimal, if any, muscle dissection and they can be performed under local anesthesia. However, one drawback associated with minimally invasive procedures is the relatively small amount of working space available to the surgeon adjacent the cannula or sleeve providing access to the surgical site. Minimally invasive spinal surgery is the future of spinal surgery. However, there are few new minimally invasive systems on the market, all in the infancy in their design. Most of the existing systems are crude in respect to the demands required by a minimally invasive spinal surgeon. Limitations of these new minimally invasive systems include inadequate lighting, limited visualization, poor surgical site access, cumbersome instrument access, poor retraction of deep tissue and crowding of instruments into the portal.
A need exists, therefore, for an improved minimally invasive system which will eliminate the above type limiting factors of the presently existing instruments on the market.
A need also exists for a system which will provide greater flexibility in a surgical retractor system while improving both visual and physical access by the surgeon to the surgical field. In the case of spinal surgery, a need exists for such improved instruments and techniques which will provide for safe and effective disc space preparation and implant insertion while minimizing trauma to tissue surrounding the surgical site.